This invention relates to a feed for swine containing a casein digestion product of which a principal component is casein phosphopeptide (CPP), and to a method of breeding a swine using the same.
Recently, development in technics is remarkable in the production field of edible animals, such as the improvement in breeding environment, the extension of scale, the improvement of breed and the improvement in feeding system, resulting in the improvement in productivity.
It is necessary for feed to contain various nutrients at a suitable blending ratio in order to conserve the animal life. However, various problems occur due to insufficient nutrient absorption. For example, in the case of piglet, born growth cannot overtake body weight increase due to insufficient utilization of minerals, such as calcium, and problems of weak leg, split of hoof, and so on occur. On the other hand, in the case of breed sow, problems occur, such as weak leg due to insufficient mineral absorption during breeding piglets and insufficient mineral supply to fetuses from pregnant sow. In view of these circumstances, various minerals, such as calcium, are sufficiently added to feeds for breed sow and piglet, as well as phosphorus, various vitamins and so on. Nevertheless, problems of weak leg, split of hoof, inferiority in milk quality, inferiority in piglet blood properties still remained.
On the other hand, CPP is known as a calcium absorption-promoting factor for human, and the properties have been elucidated (H. Naito, Kagaku To Seibutsu, 18, 551-558, 1980, Y. S. Lee, et al., Brit. J. Nutr., 43, 457-467, 1980, Bifidobacterium Microflora, 6(1), 1-6, 1986, U.S. Pat. No. 4,816,398). However, it is not known to add CPP to a feed for swine.